PCIe Scaling Summary
While most games show only modest differences between various slot configurations, Call of Duty: Modern Warfare 2’s unusually high variance accounts for 20% of our benchmark totals.
Builders can expect an average performance loss of 8% when going from a x16 to a x8 slot. That could be an important consideration when using a platform that has a limited number of PCI Express lanes, such as an LGA 1156 platform in SLI mode. But before we move on to the SLI tests, let’s see what effect these configurations have on power, heat, and efficiency.
Dropping PCIe lanes can reduce power consumption, but not enough to matter to most high-end PC owners.
We wouldn’t expect a difference in heat simply from using a different slot, so we weren’t surprised to find that none existed.
Losing moderate performance without a similarly-sized reduction in power is a recipe for an efficiency disaster, since the calculation compares performance to power.
Now that we know to expect an 8% average performance loss when moving a single GeForce GTX 480 from a x16 to a x8 PCIe 2.0 slot, let’s see how that difference translates to SLI. Do we really need more than sixteen PCIe lanes to support two high-end graphics cards?
You spend unnecessary $$$ on a x58 platform while I save money that I can put towards a GPU upgrade with my p55 platform :)
anyone know if 4850's are going to be unavailable any time soon? You could get the 3000 series for quite awhile after the 4000's released so I'm crossing my fingers until i can afford a cpu upgrade and another 4850
cpu is currently a 7750BE and so im pretty sure it would bottleneck the 4850's. I think it does with just one actually.
It's not the game's fault. The GPU can only go as fast as it was made to go. So in simple terms you could say that GPUs these days aren't "fast" enough to use all the bandwidth PCI Express offers.
On a card for card basis they are still quite a bit more powerful than the GTX 480 and should require the most bandwidth of any current card for maximum performance.